CN-121990966-A - Preparation method of crystalline copper pyrrolidone carboxylate

CN121990966ACN 121990966 ACN121990966 ACN 121990966ACN-121990966-A

Abstract

The invention belongs to the technical field of organic chemistry, and discloses a preparation method of crystalline copper pyrrolidone carboxylate, which comprises the following steps: L-pyroglutamic acid is taken as a raw material, is dissolved under alkaline conditions and then is subjected to complex reaction with copper ions to obtain a copper pyrrolidone carboxylate reaction solution, the reaction solution is subjected to hot filtration to remove impurities, filtrate concentration, cooling to separate out crystals, filtration, washing and drying to obtain blue-green crystal copper pyrrolidone carboxylate. The process has the characteristics of high yield, simple and convenient post-treatment and the like. The invention provides a novel, efficient and environment-friendly industrial preparation method with low production cost.

Inventors

ZHOU YUNPENG
ZHANG QIUSHI
LIU JU
CHEN YE
LIU YUFENG
SHEN JIWEI
Qin Ruosong
Zhong Mengyan
ZHOU ZIFAN

Assignees

辽宁大学

Dates

Publication Date: 20260508
Application Date: 20260325

Claims (8)

1. The preparation method of crystal copper pyrrolidone carboxylate is characterized in that L-pyroglutamic acid is taken as a raw material, and is dissolved under alkaline conditions and then subjected to complexation reaction with copper ions to obtain a copper pyrrolidone carboxylate reaction solution, and the reaction solution is subjected to hot filtration to remove impurities, cooled to separate out crystals, filtered, washed and dried to obtain blue-green crystal copper pyrrolidone carboxylate.
2. The method for preparing crystalline copper pyrrolidone carboxylate according to claim 1, comprising the following steps: S1, dissolving L-pyroglutamic acid in a reaction solvent system through stirring, dropwise adding an alkaline solution, heating to a target temperature required by a process, adding a solution containing a certain equivalent of copper ions, carrying out a complexation reaction, and obtaining a reaction solution after the detection reaction is finished; And S2, filtering the reaction solution at a set temperature to remove insoluble impurities, cooling to separate out crystals, and filtering, washing and drying to obtain a target product of blue-green crystal pyrrolidone carboxylic acid copper.
3. The method for preparing crystalline copper pyrrolidone carboxylate according to claim 2, wherein in S1, the alkaline solution is prepared by adding inorganic base into the reaction solution, and the molar ratio of L-pyroglutamic acid to copper ion to inorganic base is 2:1-1.5:1-2.5, preferably 2:1:1.95.
4. A process for the preparation of crystalline copper pyrrolidone carboxylate according to claim 3, wherein the copper ions are derived from copper ion-containing compounds comprising one or more of copper sulfate, copper chloride, copper nitrate, basic copper carbonate, copper chloride, copper gluconate and hydrates thereof, preferably copper chloride dihydrate; the inorganic base comprises one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide and sodium bicarbonate, preferably sodium hydroxide; the reaction solvent used comprises one or more of water, isopropanol, methanol, ethanol and n-butanol, preferably aqueous solution.
5. A process for preparing crystalline copper pyrrolidone carboxylate according to claim 2, wherein in S1, The dropping of the alkaline solution is to control the pH value to be 6.5-14; The temperature is controlled to be 0-30 ℃ when the alkaline solution is dropwise added; the temperature of the complex reaction is controlled to be 20-80 ℃; the reaction is finished and the pH value is controlled to be 3-5.
6. A process for preparing crystalline copper pyrrolidone carboxylate according to claim 5, wherein in S1, The dropping of the alkaline solution is to control the pH value to be 7+/-0.5; the control temperature is 20+/-2 ℃ when the alkaline solution is added dropwise; The temperature of the complex reaction is controlled to be 60+/-2 ℃; the reaction was completed with a control ph=4.5±0.5.
7. A process for preparing crystalline copper pyrrolidone carboxylate according to claim 2, wherein in S2, The temperature of the hot filtration at the set temperature is controlled to be 20-80 ℃; The filtering temperature of the precipitated crystals is 0-60 ℃.
8. A process for preparing crystalline copper pyrrolidone carboxylate according to claim 2, wherein in S2, The temperature of the thermal filtration at the set temperature is controlled to be 70+/-2 ℃; the filtration temperature of the precipitated crystals is 10+/-2 ℃.

Description

Preparation method of crystalline copper pyrrolidone carboxylate Technical Field The invention belongs to the technical field of chemical synthesis, in particular to a preparation method of crystalline copper pyrrolidone carboxylate, and particularly relates to a simple technical scheme of industrial-grade preparation, separation and purification of crystalline copper pyrrolidone carboxylate. Background Copper pyrrolidone carboxylate, also known as copper PCA, is a copper salt of L-pyrrolidone carboxylic acid (L-PCA). L-PCA is obtained by cyclizing the amino acid L-glutamic acid of vegetable origin. Copper has antibacterial property and is one of trace elements essential to human body. Copper PCA is a combination of copper and L-PCA that regulates sebaceous gland activity by reducing skin sebum levels. It is an active ingredient of oily skin emulsions, also imparting its characteristic lagoon. Copper has many advantages in terms of skin application. Collagen, as well as connective tissue on the skin, uses copper as a catalyst in many metabolic and synthetic reactions, thereby refreshing and healthful skin. It also accelerates wound healing. Copper PCA can also be used as a colorant for cosmetics. It helps the skin clean up dead skin cells, loosen them from the epithelial site, help clean the skin, and restore the fresh appearance of the skin. Copper generally has an antibacterial effect by the same mechanism as skin. It binds to a significant part of the microorganisms, leading to their metabolic process dysfunction. Thus, problems caused by microorganisms, such as acne or redness, can be fundamentally solved. It reduces sebum secretion from the skin and prevents overactivity in the case of acne. Such an effect may help positively condition the skin affected by acne. Oily skin appears to benefit more. For body care, skin care, baby care, facial care and facial cleaning. The effects are shown in 1. Helping to repair damaged skin protection barrier, 2. Providing moisture retention hydration immediately, 3. Improving skin elasticity and firmness, 4. Improving skin luster and glossiness, 5. Reducing sunburn/erythema, etc. The recommended addition amount is 1-10% The synthesis process of copper pyrrolidone carboxylate includes the first complexing reaction of L-pyroglutamic acid with copper ion compound under alkaline condition, concentrating the reaction liquid, separating out and other post-treatment steps. The patent 201710687779.2 relates to an amino acid compound and application of a bactericidal composition thereof in agriculture, which takes L-pyroglutamic acid as a raw material, water or methanol as a solvent, adjusts the pH value to 7-8, drops into methanol or aqueous solution containing cupric chloride, reacts for 1 hour after the drop, and concentrates the solution to obtain copper pyrrolidone carboxylate solid. The specific reaction control and condition selection are not explicitly described in the patent claims, and comprise the influence of technological parameters such as temperature, pH value, solvent selection and the like on the key industrial preparation index of yield, the specific method for realizing the index and experimental data, and the qualitative analysis of the target product prepared by the synthetic method is not performed, so that the requirements of related description required by the cosmetic field applied to skin and the industrial preparation method of the product cannot be met. Disclosure of Invention The crystalline copper pyrrolidone carboxylate prepared by the method is applied to skin care and is suitable for a synthetic method of industrial preparation. The method is characterized in that L-pyroglutamic acid is used as a main raw material, and is subjected to complexation reaction with a compound containing copper ions under alkaline conditions to prepare copper pyrrolidone carboxylate reaction liquid in one step. The reaction solution is subjected to post-treatment such as impurity removal, crystallization precipitation, solid drying and the like to obtain blue-green crystal pyrrolidone carboxylic acid copper. The preparation process has the characteristics of high yield, simple and convenient post-treatment and the like, and the high-purity crystal powder is obtained. The invention provides a novel, efficient and environment-friendly industrial preparation method with low production cost. The preparation process includes two stages, reaction stage (S1) and post-treatment stage (S2), and features that S1, L-pyroglutamic acid is dissolved in the reaction solution system via stirring under alkaline condition, the temperature is raised to required target temperature, proper pH value is controlled, solution with copper ion in certain amount is added, complexation reaction is performed at set temperature, proper pH value is reached after detection reaction is completed, reaction solution is obtained, S2, insoluble impurity is eliminated through hot filtration of the reactio